That's really two different classes of products. You want to read a review before you buy a car, but by and large people actually do that already.
Low cost items don't need that because this isn't going to be the only sandwich or bottle of laundry detergent you buy this decade, so it's as easy to take a chance on it once and try it yourself as to read a review which may or may not be biased, and then if it sucks you don't buy it again.
Low cost items don't need that because this isn't going to be the only sandwich or bottle of laundry detergent you buy this decade, so it's as easy to take a chance on it once and try it yourself as to read a review which may or may not be biased, and then if it sucks you don't buy it again.